<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>示例</title>
</head>
<body>

    <div id="app">
        总价: {{ prices }}
    </div>

    <script src="https://unpkg.com/vue/dist/vue.min.js"></script>
    <script>

        var app = new Vue({
            el: "#app",
            data: {
                package1: [
                    {
                        name: 'iPhone 7',
                        price: 7199,
                        count: 2
                    },
                    {
                        name: 'iPad',
                        price: 2888,
                        count: 1
                    }
                ],
                package2: [
                    {
                        name: 'apple',
                        price: 3,
                        count: 5
                    },
                    {
                        name: 'banana',
                        price: 2,
                        count: 10
                    }
                ]

            },
            computed: {
                prices: function () {
                    var prices = 0;
                    for (var i = 0; i < this.package1.length; i++){
                        prices += this.package1[i].price * this.package1[i].count;
                    }

                    for (var i = 0; i < this.package2.length; i++){
                        prices += this.package2[i].price * this.package2[i].count;
                    }

                    return prices;
                }
            }
        });

    </script>

</body>
</html>